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authorJohannes Hofmann <Johannes.Hofmann@gmx.de>2007-03-18 12:22:50 +0100
committerJohannes Hofmann <Johannes.Hofmann@gmx.de>2007-03-18 12:22:50 +0100
commit5432343cc8bd34a77a1584be33abbd53cdd6e373 (patch)
tree01ef156b23b228220768ed021c1db127d22b7e51 /src
parent18ace785b31de59e5d60eb4507e4e991027ec795 (diff)
implement bicubic interpolation
Diffstat (limited to 'src')
-rw-r--r--src/GipfelWidget.H6
-rw-r--r--src/GipfelWidget.cxx50
-rw-r--r--src/gipfel.cxx2
3 files changed, 56 insertions, 2 deletions
diff --git a/src/GipfelWidget.H b/src/GipfelWidget.H
index 8cb6d3f..ed251ef 100644
--- a/src/GipfelWidget.H
+++ b/src/GipfelWidget.H
@@ -44,13 +44,17 @@ class GipfelWidget : public Fl_Widget {
static int get_pixel_bilinear(Fl_Image *img, double x, double y,
int *r, int *g, int *b);
+ static int get_pixel_bicubic(Fl_Image *img, double x, double y,
+ int *r, int *g, int *b);
+
static int get_pixel(Fl_Image *img, int x, int y,
int *r, int *g, int *b);
public:
typedef enum {
NEAREST = 0,
- BILINEAR = 1
+ BILINEAR = 1,
+ BICUBIC = 2
} sample_mode_t;
GipfelWidget(int X,int Y,int W, int H);
diff --git a/src/GipfelWidget.cxx b/src/GipfelWidget.cxx
index 1eb8866..2daea2a 100644
--- a/src/GipfelWidget.cxx
+++ b/src/GipfelWidget.cxx
@@ -686,6 +686,9 @@ GipfelWidget::get_pixel(GipfelWidget::sample_mode_t m,
if (m == GipfelWidget::BILINEAR) {
ret = get_pixel_bilinear(img, px + ((double) img->w()) / 2.0,
py + ((double) img->h()) / 2.0, r, g, b);
+ } else if (m == GipfelWidget::BICUBIC) {
+ ret = get_pixel_bicubic(img, px + ((double) img->w()) / 2.0,
+ py + ((double) img->h()) / 2.0, r, g, b);
} else {
ret = get_pixel_nearest(img, px + ((double) img->w()) / 2.0,
py + ((double) img->h()) / 2.0, r, g, b);
@@ -751,6 +754,53 @@ GipfelWidget::get_pixel_bilinear(Fl_Image *img, double x, double y,
}
}
+static double
+interp_cubic(double x, double *v) {
+ double a0, a1, a2, a3;
+ double x2 = x * x;
+
+ a0 = v[3] - v[2] - v[0] + v[1];
+ a1 = v[0] - v[1] - a0;
+ a2 = v[2] - v[0];
+ a3 = v[1];
+
+ return a0 * x * x2 +a1 * x2 + a2 * x + a3;
+}
+
+int
+GipfelWidget::get_pixel_bicubic(Fl_Image *img, double x, double y,
+ int *r, int *g, int *b) {
+
+ int fl_x = (int) rint(x);
+ int fl_y = (int) rint(y);
+ int ic[3];
+ double c[3][4];
+ double c1[3][4];
+
+ for (int iy = 0; iy < 4; iy++) {
+ for (int ix = 0; ix < 4; ix++) {
+ if (get_pixel(img, fl_x + ix - 2, fl_y + iy - 2,
+ &ic[0], &ic[1], &ic[2]) != 0) {
+ return 1;
+ }
+
+ for (int l = 0; l < 3; l++) {
+ c[l][ix] = (double) ic[l];
+ }
+ }
+
+ for (int l = 0; l < 3; l++) {
+ c1[l][iy] = interp_cubic(x - fl_x, c[l]);
+ }
+ }
+
+ *r = (int) rint(interp_cubic(x - fl_x, c1[0]));
+ *g = (int) rint(interp_cubic(x - fl_x, c1[1]));
+ *b = (int) rint(interp_cubic(x - fl_x, c1[2]));
+
+ return 0;
+}
+
int
GipfelWidget::get_pixel(Fl_Image *img, int x, int y,
int *r, int *g, int *b) {
diff --git a/src/gipfel.cxx b/src/gipfel.cxx
index 410471d..8620641 100644
--- a/src/gipfel.cxx
+++ b/src/gipfel.cxx
@@ -497,7 +497,7 @@ int main(int argc, char** argv) {
type |= STITCH_VIGNETTE_CALIB;
}
- stitch(bilinear_flag?GipfelWidget::BILINEAR:GipfelWidget::NEAREST,
+ stitch(bilinear_flag?GipfelWidget::BICUBIC:GipfelWidget::NEAREST,
stitch_w, stitch_h, stitch_from, stitch_to,
type, outpath, my_argc, my_argv);